The weather didn't let us down on March 11, the last day of the intensive phase of the campaign. Temperatures were still pretty low, around -42°C at the weather station and just below -30°C at the Ridge Lab, and the wind had picked up slightly at the lab. Even though there were occasional clouds, with the Sun being up for more than 9.5 hours now, the team was granted excellent measurement conditions for most of their final day. They made their way up to the Ridge Lab around 8:30 AM, stopping briefly at the 80°N sign for some more pictures. After getting everything ready to hand over to Pierre and Andrew, the team made sure to sign the guest book at the Ridge Lab before heading down to the weather station for dinner and an evening at the rec room.
Since March 11 was the last day at the Ridge Lab, much of Tyler's and Beatriz's time was spent getting everything in order for Pierre and Andrew, who will continue to run the Bruker 125HR and EM27/SUN during the extended phase of the campaign. Tyler spent some time writing up a quick reference guide for the Bruker 125HR macro measurements, a document detailing the operation of the Vaisala PTU30T pressure sensor and Raspberry Pi, as well as a quick guide for operating and packing the EM27/SUN. Beatriz worked on updating the Standard Operating Procedures (SOP) document for the Bruker 125HR to reflect changes in the macros and measurement procedures. The morning was cloudy, and solar measurements were only possible around 10 AM. Tyler and Beatriz operated the Bruker 125HR in mid-infrared mode from 10 to 11 AM, then they switched the beamsplitter from the KBr to the CaF2 one used in near-infrared measurements. They then collected 50 near-infrared TCCON spectra over the course of two hours, before switching back to mid-infrared measurements at the end of the day. Overall, they collected 24 mid-infrared spectra across all seven filters, and 50 near-infrared spectra. The EM27/SUN was measuring from 10 AM until 4:30 PM, and Tyler and Beatriz collected around 1700 interferograms with it over the course of the day.
On the last day of the campaign, Kristof and Ramina began their day at the Ridge Lab with an instrument check on the roof and inside the lab. They will continue to monitor the PEARL-GBS and UT-GBS instruments remotely for the remainder of the measurement period. The team also spent some time organizing the lab space and packing up some motor components which will be shipped for repairs.
Ali started the DIAL around 9:15 PM on the night from March 10 to March 11. The DIAL ran about 1 hour after which the signal unfortunately dropped due to clouds and snow. Ali and Alexey turned off the DIAL and checked the weather frequently but the conditions didn't change, so they couldn't make any further observation for that night. On the morning of March 11, Ali and Alexey spent several hours to shut down the DIAL for the end of the season.
An ozonesonde was launched at 6:15 PM on March 11 and reached a final altitude of 15706 m (84.1 hPa).
To round off an amazing campaign, the wolves showed up at Eureka in the evening. A pack of about 8 animals passed right through the station and the team was able to see them close up from the truck.
The past three weeks have flown by incredibly fast and even though the team is looking forward to getting back to Toronto by the end of the week, we will sorely miss the friendliness of the Eureka Weather Station staff. We really appreciate all that they have done for us to support the campaign and our team in Eureka. We would like to thank Scott McCormick, the station program manager, for his warm welcome, sharing his knowledge and experiences with us and, together with Andrew Creighton (SPM-in-training) giving us the unique opportunity of seeing and climbing the icebergs in the fiord. There's nothing better than a great meal to make you feel at home, and Daryl McLaughlin and Flora Neiley made sure we had plenty of them, which we highly appreciate. Needless to say we will spread the word about the most amazing fruit crumble, that Flora so generously shared with us, down south and around the world, and the Eureka rose rocks will certainly travel no less. We would also like to thank CANDAC operator Andrew Hall for getting us up to the lab and back to the weather station, and starting our days at the lab with freshly brewed coffee. Thanks a lot to the Eureka weather station staff, Peter Chachula, the Senior Aerological Observer, and Cole Watson and Alex Araujo, the meteorological technicians for involving us in and always keeping us up to date on the ozonesonde launches; to Jay Roberts for keeping the roads clear for us, and to mechanic John Oakoak for keeping everything up and running and for sharing his stunning pictures with us.
Cheers,
Ellen Eckert
[on behalf of the 2020 Canadian Arctic ACE/OSIRIS Validation Campaign]